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761.
A laboratory experiment was conducted to investigate the longterm effects of amending sulfide-rich lignite mine spoil with fly ash (originating from a coal-fired power station and largely comprised of aluminosilicates) and/or agricultural limestone. The experiment was carried out with soil moisture maintained at field capacity or alternate cycles of wetting and drying. Results obtained suggest that the principal acidification processes were oxidation of sulfide and formation of hydroxysulfate (FeOHSO4), whereas the main neutralization processes were weathering of aluminosilicates in fly ash-treated samples and dissolution of calcium carbonate in limestone-treated samples. The highest dose of limestone rapidly raised the pH of the spoil, but this increase was not maintained throughout the one-year experiment. In contrast, fly ash-treated samples showed a more sustained increase in pH, attributable to the gradual weathering of aluminosilicates. The best results (i.e., good short- and long-term neutralization) were obtained in samples treated with both fly ash and limestone. The low liming capacity of the fly ash (47.85 cmol kg(-1)) means that it must be used in large quantities, an advantage in achieving the further aim of disposing of the fly ash. 相似文献
762.
The introduction of environmental education (EE) in school centres is a process which has mainly followed two paths. One centred on teaching actions, on the curriculum organization and administration in order to enable educational practice orientated towards attaining the aims of EE. The other, which is here denominated 'organizational strategy' focuses, basically, on the organization and administration of the centre from an environmental perspective. The characteristics and main results of this 'environmental education and school organization' research project are described, dedicating special attention to the assessments of some of the participants. A series of elements for discussion and debate which could be useful in the development of future projects and actions within the framework of school organization greening is presented. 相似文献
763.
This article analyzes what motivates companies to obtain ISO 14001 certification and what factors within companies determine the success or failure of the environmental management standard. The most important motivators appear to be the worldwide recognition accorded the ISO 14000 norm, and its applicability to all sectors. The factors that most contribute to success are the company's experience in management systems and involvement by management. Failure most often results from lack of employee training and organizational rigidity. © 2001 John Wiley & Sons, Inc. 相似文献
764.
P. W. Glynn S. B. Colley J. L. Maté J. Cortés H. M. Guzman R. L. Bailey J. S. Feingold I. C. Enochs 《Marine Biology》2008,153(4):529-544
The reproductive ecology of Tubastraea coccinea Lesson, an azooxanthellate tropical scleractinian coral, was studied over various periods from 1985 to 2006 at four principal
eastern Pacific locations in Costa Rica, Panamá, and the Galápagos Islands (Ecuador). This small (polyp diameter 0.8–1.0 cm),
relatively cryptic species produced ova and planulae year round, including colonies with as few as 2–10 polyps. Of 424 colonies
examined histologically, 13.7% contained both ova and sperm. Mature ova varied in diameter from ∼300 to 800 μm and the time
from spawning and fertilization of oocytes to release of brooded planulae was about 6 weeks. Planulae were 0.5–1.5 mm long
and they settled and metamorphosed on a variety of substrates after 1–3 days. Spermaries, though more difficult to distinguish
in histological sections, were present throughout the year. Spent spermaries were never observed in sections, but several
colonies in Panamá and the Galápagos Islands released sperm from night one to night five after full moon, indicating the potential
for cross-fertilization among colonies. Planula release was observed at Uva Island (Panamá) in March, May, June, and July,
and in general planula presence was higher at warm ocean temperatures at all sites, whether or not the sites were influenced
by seasonal upwelling. Annual fecundity estimates for T. coccinea are comparable with other high fecundity brooding species, including the zooxanthellate Porites panamensis, with which it co-occurs in Panamá. Tubastraea coccinea is widely distributed in the tropical Indo-Pacific and has colonized substrates in the western Atlantic. In addition to the
reproductive characteristics described in the present study, other features of the biology of T. coccinea, such as an ability to withstand conditions that produce bleaching and mortality in zooxanthellate species, may account for
its widespread, low-latitude distribution in multiple oceans.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
An erratum to this article can be found at 相似文献
765.
Ilie S. Racotta Elena Palacios Ana M. Ibarra José Luis Ramírez Fabiola Arcos Olivia Arjona 《Marine Biology》2008,153(6):1245-1256
Induction of triploidy in aquatic organisms has increased worldwide in the last two decades, mostly because triploids have
better growth than diploids. According to a physiological hypothesis, partial or total sterility of triploids allows the accumulation
of reserves in muscle and other tissues instead of being transferred to the gonad. The present study analyzes lipid, protein,
carbohydrate, and fatty acid levels in muscle and gonads of Nodipecten subnodosus triploids and diploids over 18 months from June 2001 to December 2002. An important increase in gonadosomatic index of diploids
scallops was observed from May to June 2002 reaching the highest values in August. Such increase was not observed in triploid
scallops. Changes in biochemical composition in female gonad were in general related to the accumulation of reserves during
gonad development of diploid scallops. This accumulation was lower for triploid scallops, in accordance to their sterility,
especially for carbohydrates and acylglycerides. Adductor muscle index as well as protein and carbohydrate levels in muscle
increased in both ploidy groups during the reproductive period indicating no mobilization of reserves to sustain gonad development
in both ploidy groups. These results partially support the physiological hypothesis on the advantage of triploids: in a rich
food locality no mobilization of reserves is needed to sustain gametogenesis. This, together with a possible lower efficiency
of energy assimilation at high food concentration for triploids, may be the reason for an apparent lack of superiority of
N. subnodosus triploids in terms of adductor muscle growth. Only the levels of particular highly unsaturated fatty acids levels (namely
20:4n-6 and 20:5n-3) in muscle of diploid and triploid decreased during the reproductive period, indicating a possible transfer of selected
fatty acids to gonads, even in triploids. The muscle of triploids has a slightly but significantly higher proportion of 22:6n-3 compared to diploids, which can have implications for the nutritional and commercial value of triploid adductor muscle. 相似文献
766.
767.
M. Byrne T. A. A. Prowse M. A. Sewell S. Dworjanyn J. E. Williamson D. Vaïtilingon 《Marine Biology》2008,155(5):473-482
Lipid and protein biochemistry of eggs (84 μm in diameter), embryos and early larvae of the tropical echinoid Tripneustes gratilla (Linnaeus 1758) were quantified to determine how maternal provisions are used to fuel development of the echinopluteus. The
eggs contained a mean of 30.82 ng lipid and 87.32 ng protein. Energetic lipids were the major lipid component (55.52% of total
lipid) with the major class being triglyceride (TG: mean 15.9 ng, 51.58% of total). Structural lipid was dominated by phospholipid
(PL: mean 11.18 ng, 36.26% of total). Early embryogenesis was not a major drain on egg energetic lipid and protein. Development
of the functional feeding larva used ca. 50% of initial egg energetic lipid and most of this was TG. Maternal TG was still
present in the 8-day echinoplutei and it was estimated that this energetic lipid would be depleted in unfed larvae by day
10. There was no change in PL. In a separate experiment lipid biochemistry of rudiment stage larvae and early developing juveniles
were quantified to determine how lipids are used during metamorphosis. Fed larvae accumulated lipid (mean 275.49 ng) with
TG and PL being the major energetic and structural lipids, respectively. Larval lipid stores were not appreciably depleted
by metamorphosis and so were available for the early benthic stage juvenile. Juveniles started their benthic existence with
314 ng total lipid (TG: mean 46.84 ng, 14.9% of total, PL: mean 137.51 ng, 43.67% of total). Nile Red histochemistry and histology
showed that the stomach serves as a nutrient storage organ and, that lipid stores accrued by larvae sustain developing juveniles
for up to 4 days post settlement. Triglyceride supported both non-feeding stages of development and the prefeeding larval
and perimetamorphic benthic stage. In this first study of lipid stores in settlement stage echinoderm larvae, we show that
T. gratilla larvae sequester the same major energetic lipid (TG) to support the early juvenile that the female parent provided them to
fuel early development. 相似文献
768.
Csaba Moskát Jesús M. Avilés Miklós Bán Rita Hargitai Anikó Zölei 《Behavioral ecology and sociobiology》2008,62(12):1885-1890
Common cuckoo (Cuculus canorus) parasitism drastically reduces the reproductive success of their hosts and selects for host discrimination of cuckoo eggs.
In a second stage of anti-parasite adaptation, once cuckoos can lay eggs that mimic those of their hosts, a high uniformity
of host egg appearance within a clutch may favour cuckoo egg discrimination. Comparative evidence provides indirect support
for this hypothesis although experimental support is currently lacking. Here, we studied the effect of experimentally decreased
uniformity of host egg appearance on cuckoo egg discrimination by great reed warbler (Acrocephalus arundinaceus) hosts in a population in which long-term cuckoo parasitism has led to high levels of cuckoo–host egg mimesis. We manipulated
host clutch uniformity by adding extra spots to fresh host eggs just after they were laid. Rejection of non-mimetic experimental
eggs added to these nests was compared with those in control nests in which uniformity was not altered. Previously, by over-painting
real spots in a control group of nests, we showed a negligible effect of our paints on hosts’ perception of their eggs. We
show that for the great reed warbler, non-mimetic experimental eggs were relatively more tolerated in experimental nests,
i.e. with lower uniformity (40%) than in control nests (5%). This is the first experimental study, to our knowledge, which
demonstrates a reduced discrimination of foreign eggs as a consequence of an increase of egg phenotypes variation perception
in a cuckoo host. 相似文献
769.
Elizabeth A. Langridge Ana B. Sendova-Franks Nigel R. Franks 《Behavioral ecology and sociobiology》2008,62(12):1851-1861
Colonies of the ant Temnothorax albipennis improve their collective performance over successive emigrations (Langridge et al. Behav Ecol Sociobiol 56:523–529, 2004,
Behav Ecol Sociobiol 62:447–456, 2008). Here, by analysing the performance of individual transporters (workers that carry
the brood, queen and a proportion of adults), we investigate whether they spend less time at the old and new nests during
repeated emigrations. Transporters expedited choosing and picking up brood items at the old nest and depositing them in the
new nest. Such improvements were not associated with adult transport. Generally, when carrying brood items, but not when carrying
adults, transporters visited several locations in the new nest before depositing them. Transporters did not interact with
other adults when depositing brood items. Consequently, reductions in depositing times are the sum of time savings made by
individual transporters. By contrast, transporters spent most time interacting with other adults before picking up brood items
at the old nest. As the frequency of these interactions did not decline, we suggest the behaviours of interacting adults were
modified in a way that hastened their completion. Thus, reductions in picking-up times probably occur because of time saved
during interactions. 相似文献
770.
Veronika Bókony László Zsolt Garamszegi Katharina Hirschenhauser András Liker 《Behavioral ecology and sociobiology》2008,62(8):1229-1238
Despite the functional significance of melanin-based plumage coloration in social and sexual signaling, the mechanisms controlling
its information content are poorly understood. The T-regulation hypothesis proposes that melanin ornaments signal competitive
abilities via the effects of testosterone (T) mediating both melanization and sexual/aggressive behaviors. Using the phylogenetic
comparative approach, we tested whether frontal black melanization is associated with elevated T around the time of breeding
plumage development across all bird species with available T-data. We found a context-dependent relationship between melanization
and T, varying with the type of ornamentation (patchy or full-black) and with the presumed taxonomic distribution of the hormonal
control of plumage dichromatism. Within two taxa in which male plumage development is assumed androgen-dependent (Charadriiformes,
Corvida), evolutionary increases in male melanization, and melanin dichromatism correlated with increases in T in most analyses
but not within the basal lineage (ratites, Galloanseriformes) with androgen-independent male plumage. Among Passeroidea with
presumably genetically or luteinizing-hormone-based male plumage, melanization and its dichromatism correlated with T only
in species with <100% frontal melanization. These results were robust as we controlled for several confounding variables such
as mating and parental behaviors. This study is the first to test and support the T-regulation hypothesis interspecifically,
suggesting that among-species differences in melanization may have evolved in response to differences in circulating T in
certain avian taxa. Our results imply that the extent of black ornamentation may serve as an honest indicator of male competitiveness
in those species that evolved an appropriate hormonal basis (T dependence) for color production.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献